As illustrated in FIG. 12, a sealing device is provided between a rotating shaft 1 of a compressor and a housing hole 2a of a housing 2 in a refrigerating machine provided in a cooling apparatus, for example. The sealing device prevents leakage of a fluid, such as refrigerant gas and refrigerating machine oil, enclosed in the housing 2, to the outside through a gap between the housing 2 and the rotating shaft 1. The sealing device includes a reinforcing ring 3, an exterior sealing member 4, an auxiliary sealing member 5, and a retainer 6.
The reinforcing ring 3 is a cylindrical member formed of metal. The reinforcing ring 3 has an inside diameter that is larger than an outside diameter of the rotating shaft 1, and the reinforcing ring 3 has an outside diameter that is smaller than an inside diameter of the housing hole 2a. A pinching base portion 3a is formed in the reinforcing ring 3. The pinching base portion 3a is bent at a substantially right angle, and a leading end portion of the pinching base portion 3a is orientated toward a central portion side.
The exterior sealing member 4 is molded using an elastomer that has rubber-like elasticity. The exterior sealing member 4 includes a fitting portion 4a and a sealing lip portion 4b. The fitting portion 4a is provided such that an outer circumference portion of the reinforcing ring 3 is covered therewith. The sealing lip portion 4b is extended from one end portion of the reinforcing ring 3. The fitting portion 4a is molded such that an outside diameter of the fitting portion 4a is larger than an inside diameter of the housing hole 2a. The sealing lip portion 4b is formed into a tapered cylindrical shape such that an inside diameter of an extended end portion of the sealing lip portion 4b is smaller than an outside diameter of the rotating shaft 1. The exterior sealing member 4 is integrally formed with the reinforcing ring 3 by curing adhesion.
The auxiliary sealing member 5 includes a cylindrical sealing lip portion 5a and a flange portion 5b that is extended radially outward from one end portion of the sealing lip portion 5a. The auxiliary sealing member 5 is molded using a synthetic resin material whose rigidity is higher than that of the elastomer. An inside diameter of the sealing lip portion 5a is smaller than an outside diameter of the rotating shaft 1.
The retainer 6 formed of metal is mounted inside the reinforcing ring 3. An inner cylinder portion 6a and a pinching portion 6b are provided in the retainer 6. An outside diameter of the inner cylinder portion 6a is smaller than an inside diameter of the reinforcing ring 3. The pinching portion 6b is formed into a circular disk that is extended toward a central portion from one end portion of the inner cylinder portion 6a. An insertion hole is formed in the central portion of the pinching portion 6b such that the rotating shaft 1 is inserted therethrough. The retainer 6 is mounted in the reinforcing ring 3 while the auxiliary sealing member 5 is disposed. The retainer 6 pinches and retains the flange portion 5b of the auxiliary sealing member 5 between the pinching portion 6b and the pinching base portion 3a of the reinforcing ring 3.
In the sealing device configured as described above, the sealing lip portion 4b of the exterior sealing member 4 is mounted in the housing hole 2a while orientated inward of the housing 2, and the rotating shaft 1 is inserted through the central portion thereof. At this point, the reinforcing ring 3 presses the fitting portion 4a of the exterior sealing member 4 against an inner circumference surface of the housing hole 2a. A leading end portion of the sealing lip portion 4b of the exterior sealing member 4 is pressed against an outer circumference surface of the rotating shaft 1. An inner circumference surface of the sealing lip portion 5a of the auxiliary sealing member 5 is pressed against an outer circumference surface of the rotating shaft 1. The leading end portion of the sealing lip portion 4b of the exterior sealing member 4 is supported from the inner circumference side by the sealing lip portion 5a. 
As a result, a gap between the housing hole 2a that is formed in the housing 2 and the rotating shaft 1 of the compressor is sealed by the exterior sealing member 4 and the auxiliary sealing member 5 so that the leakage of the fluid, such as the refrigerant gas and the refrigerating machine oil, from the inside of the housing 2 to the outside can be prevented (for example, see Patent Document 1).    Patent Document 1: Japanese Laid-open Patent Publication No. 7-305773 (FIG. 1)